soc/intel/meteorlake: Adjust Power State Current 2 threshold

VccSA Power State 2 (PS2) current threshold has be adjusted to 10A to
improve PS2 residency which reduces Voltage Regular (VR) power loss.

BUG=b:308002192
TEST=power and performance analysis shows a positive Load Line result

Change-Id: I2da2b05de8a04f91dacaa55062165c4351422865
Signed-off-by: Jeremy Compostella <jeremy.compostella@intel.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/78653
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Eric Lai <ericllai@google.com>
Reviewed-by: Kapil Porwal <kapilporwal@google.com>
Reviewed-by: Sukumar Ghorai <sukumar.ghorai@intel.com>
Reviewed-by: Subrata Banik <subratabanik@google.com>

src/soc/intel/meteorlake/chip.h

@@ -306,6 +306,30 @@ struct soc_intel_meteorlake_config {
 	 */
 	uint16_t fast_vmode_i_trip[NUM_VR_DOMAINS];
 
+	/*
+	 * Power state current threshold 1.
+	 * Defined in 1/4 A increments. A value of 400 = 100A. Range 0-512,
+	 * which translates to 0-128A. 0 = AUTO. [0] for IA, [1] for GT, [2] for
+	 * SA, [3] through [5] are Reserved.
+	 */
+	uint16_t ps_cur_1_threshold[NUM_VR_DOMAINS];
+
+	/*
+	 * Power state current threshold 2.
+	 * Defined in 1/4 A increments. A value of 400 = 100A. Range 0-512,
+	 * which translates to 0-128A. 0 = AUTO. [0] for IA, [1] for GT, [2] for
+	 * SA, [3] through [5] are Reserved.
+	 */
+	uint16_t ps_cur_2_threshold[NUM_VR_DOMAINS];
+
+	/*
+	 * Power state current threshold 3.
+	 * Defined in 1/4 A increments. A value of 400 = 100A. Range 0-512,
+	 * which translates to 0-128A. 0 = AUTO. [0] for IA, [1] for GT, [2] for
+	 * SA, [3] through [5] are Reserved.
+	 */
+	uint16_t ps_cur_3_threshold[NUM_VR_DOMAINS];
+
 	uint8_t PmTimerDisabled;
 	/*
 	 * SerialIO device mode selection:

src/soc/intel/meteorlake/chipset.cb

@@ -17,6 +17,10 @@ chip soc/intel/meteorlake
 	# Reduce the size of BasicMemoryTests to speed up the boot time.
 	register "lower_basic_mem_test_size" = "true"
 
+	# The power state current threshold is defined in 1/4 A
+	# increments. A value of 400 = 100A.
+	register "ps_cur_2_threshold[VR_DOMAIN_SA]" = "40" # 10A
+
 	# NOTE: if any variant wants to override this value, use the same format
 	# as register "common_soc_config.pch_thermal_trip" = "value", instead of
 	# putting it under register "common_soc_config" in overridetree.cb file.

src/soc/intel/meteorlake/romstage/fsp_params.c

@@ -238,6 +238,12 @@ static void fill_fspm_vr_config_params(FSP_M_CONFIG *m_cfg,
 				m_cfg->IccLimit[domain] = config->fast_vmode_i_trip[domain];
 			}
 		}
+		if (config->ps_cur_1_threshold[domain])
+			m_cfg->Psi1Threshold[domain] = config->ps_cur_1_threshold[domain];
+		if (config->ps_cur_2_threshold[domain])
+			m_cfg->Psi2Threshold[domain] = config->ps_cur_2_threshold[domain];
+		if (config->ps_cur_3_threshold[domain])
+			m_cfg->Psi3Threshold[domain] = config->ps_cur_3_threshold[domain];
 	}
 }